This invention relates to windows of the so-called vent or awning type and more particularly to windows of such type having emergency egress mountings, as well as to procedures for adapting vent or awning-type windows for emergency egress.
As herein contemplated, a vent or awning-type window comprises one or more panes each carried in a sash mounted for pivotal movement about a horizontal axis between open and closed positions. A typical window of this type, as widely used in residential buildings, includes two vent sashes, disposed one above another in a common frame in an exterior building wall. Each of the sashes is movably mounted in the frame by means of hinges secured to the sides of the sash and links connected to the hinges,which are also connected to vertically slidable draw bars respectively disposed along opposite sides of the frame and moved up and down (to close and open the sashes) by a conventional crank-type mechanism accessible from the building interior. A screen may be removably mounted in the frame inwardly of the sashes. It will be understood that the terms "inner" or "inwardly" and "outer" or "outwardly" as used herein refer respectively to directions toward the interior and toward the exterior of the building.
Present-day building codes commonly require that a clear opening (typically at least 5 ft..sup.2 in area, or even greater) be provided in an exterior wall of any residential room having only a single door, in order to permit egress of the room's occupants in case of fire or other emergency that prevents use of the door. An ordinary vent-type window may have an overall opening of the requisite area, but owing to the presence of plural vent sashes, which obstruct egress through the opening, such vent windows do not satisfy the aforementioned building code requirements. It is often not desirable or practicable to provide a single-vent window having a large enough opening for emergency egress, because a single vent of the requisite size is vulnerable to dislodgment by wind when open, with the result that the operating mechanism for the vent may break, or the vent may even be blown away.
Heretofore, it has been proposed to mount various kinds of windows with devices permitting the removal of sashes for emergency egress. These devices, however, have in general been unsatisfactory because of the time and force required to release a sash. Thus, if threaded elements are used, they must be unscrewed, and if (as sometimes happens) they are excessively tight, a tool such as pliers must be employed to disengage them. L-shaped pins that rotate from a locked position to a vent release position are also known, but again they are sometimes excessively tight and must be pried open with a screwdriver or other tool. For reasons of safety, it would be desirable to provide a window structure affording assured quick release of sashes in emergency situations, for clearing the window opening for egress.